Notice that is shows the SG disabled.
If you do a Enable-StorageGroupCopy -identity “<SourceSever\StorageGroup>” -StanbyMachine <SCRTargetServer> you will see the following:
When you try to enable the SG for SCR it states that it is already enabled for SCR. If you open look at the AD attribute msExchStandbyCopyMachines you will see that it is populated with the target machine as it should be when it is enabled.
To get past this issue do the following:
1. Remove the host entries from the hosts file.
2. Open a command prompt and run : ipconfig /flushdns
3. Restart the Microsoft Exchange Replication Service on both the Source and Target servers.
This will resolve the issue and get you back to a workable state. Now depending on how long this issue has been occuring you may need to reseed your target. To do so follow the step to reseed from the following Microsoft KB article: